Difficulty is - as always - quite high.
But players help a lot; sending X regents into harms way (be it Ilien or Caelwode) constitutes accepting extreme risk.
And lets be honest; when you look at Ilien, you can only win by treachery or adventure...so it makes sense for Ilien to prepare for that, no? And the DDC was high to begin with.
(I won't even mention Caelwode...)